Page authors: Don Knoke, David Giblin
Pseudognaphalium thermale
slender cudweed, northwestern rabbit-tobacco

Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana and Utah.

Habitat: Dry, sandy banks and ditches, open woods of ponderosa pine and Douglas fir, and mixed deciduous forests.

Flowers: June-September

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bees, flies, beetles, wasps


Herbaceous perennials, the stems 30-70 cm. tall, loosely white-woolly, not glandular.


Leaves alternate, oblanceolate to linear, 3-8 cm. long and 3-6 mm. wide, with a wing down the stem below each leaf 4-15 mm. long, the blades loosely white-woolly and with sessile glands.


Heads in loose to dense, flat-topped inflorescences; involucres broadly top-shaped, 5-6 mm. long; involucral bracts in 3-4 series, usually shiny and whitish, glabrous, ovate to oblong; corollas all tubular, the outer pistillate, 35-55, the inner perfect, 4-7; pappus of capillary bristles.


Achenes rigid, roughened.

Accepted Name:
Pseudognaphalium thermale (E.E. Nelson) G.L. Nesom
Publication: Sida. 21: 781. 2004.

Synonyms & Misapplications:
Gnaphalium canescens DC. ssp. thermale (E.E. Nelson) Stebbins & D.J. Keil
Gnaphalium microcephalum Nutt. ssp. thermale (E.E. Nelson) G.W. Douglas
Gnaphalium microcephalum Nutt. var. thermale (E.E. Nelson) Cronquist [HC]
Pseudognaphalium canescens (DC.) Anderb. ssp. thermale (E.E. Nelson) Kartesz
Pseudognaphalium microcephalum (Nutt.) Anderb., misapplied [FNA19]
Additional Resources:

PNW Herbaria: Specimen records of Pseudognaphalium thermale in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Pseudognaphalium thermale checklist entry.

OregonFlora: Pseudognaphalium thermale information.

E-Flora BC: Pseudognaphalium thermale atlas page.

CalPhotos: Pseudognaphalium thermale photos.

USDA Plants: Pseudognaphalium thermale information.

36 photographs:
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